A280638 -id:A280638 - cp's OEIS frontend

A280589 Sum of odd divisors of Bell(n).

1, 1, 1, 6, 24, 14, 240, 878, 1872, 34560, 143840, 542880, 4421376, 27644438, 97250652, 1666163520, 10523628456, 30946448412, 779556556800, 5873176163328, 15288823623792, 633207380826720, 6399554302310400, 22325251164046200, 594616643557427040, 5146116019164933120

Offset: 0

Vincenzo Librandi, Jan 07 2017

nonn

Amiram Eldar, Table of n, a(n) for n = 0..104 (terms 1..70 from Vincenzo Librandi)

Cf. A000110, A000593, A280638.

a[n_]:=Select[Divisors[BellB[n]], OddQ]//Total; Table[a[n], {n, 0, 40}]

a(n) = A000593(A000110(n)).

Offset 0 and a(0) added by Amiram Eldar, Nov 23 2019

A280727 Number of even divisors of Bell(n).

Original entry on oeis.org

0, 0, 1, 0, 0, 4, 0, 0, 24, 0, 0, 8, 0, 0, 4, 0, 0, 20, 0, 0, 24, 0, 0, 8, 0, 0, 16, 0, 0, 32, 0, 0, 16, 0, 0, 48, 0, 0, 8, 0, 0, 32, 0, 0, 32, 0, 0, 64, 0, 0, 16, 0, 0, 32, 0, 0, 1152, 0, 0, 16, 0, 0, 4, 0, 0, 16, 0, 0, 16, 0, 0

Offset: 0

Vincenzo Librandi, Jan 08 2017

nonn

Amiram Eldar, Table of n, a(n) for n = 0..112

Cf. A000110, A183063, A280589, A280638.

f[n_]:=Block[{d=Divisors[BellB[n]]}, Count[EvenQ[d], True]]; Table[f[n], {n, 0, 60}]

a(n) = A183063(A000110(n)).

Offset corrected by Amiram Eldar, Nov 23 2019

cp's OEIS Frontend

A280589 Sum of odd divisors of Bell(n).

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